1 #!/usr/bin/env python 2 3 """ 4 Translate programs. 5 6 Copyright (C) 2015, 2016, 2017 Paul Boddie <paul@boddie.org.uk> 7 8 This program is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free Software 10 Foundation; either version 3 of the License, or (at your option) any later 11 version. 12 13 This program is distributed in the hope that it will be useful, but WITHOUT 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more 16 details. 17 18 You should have received a copy of the GNU General Public License along with 19 this program. If not, see <http://www.gnu.org/licenses/>. 20 """ 21 22 from common import CommonModule, CommonOutput, \ 23 first, get_builtin_class, init_item, is_newer, \ 24 predefined_constants 25 from encoders import encode_access_instruction, encode_access_instruction_arg, \ 26 encode_function_pointer, encode_literal_instantiator, \ 27 encode_instantiator_pointer, encode_path, encode_symbol, \ 28 encode_type_attribute, is_type_attribute 29 from errors import InspectError, TranslateError 30 from os.path import exists, join 31 from os import makedirs 32 from referencing import Reference, combine_types 33 from results import Result 34 from transresults import TrConstantValueRef, TrInstanceRef, \ 35 TrLiteralSequenceRef, TrResolvedNameRef, \ 36 AliasResult, AttrResult, Expression, InstantiationResult, \ 37 InvocationResult, LogicalOperationResult, \ 38 LogicalResult, NegationResult, PredefinedConstantRef, \ 39 ReturnRef 40 from StringIO import StringIO 41 import compiler 42 import sys 43 44 class Translator(CommonOutput): 45 46 "A program translator." 47 48 def __init__(self, importer, deducer, optimiser, output): 49 self.importer = importer 50 self.deducer = deducer 51 self.optimiser = optimiser 52 self.output = output 53 54 def to_output(self, reset=False, debug=False, gc_sections=False): 55 56 "Write a program to the configured output directory." 57 58 # Make a directory for the final sources. 59 60 output = join(self.output, "src") 61 62 if not exists(output): 63 makedirs(output) 64 65 # Clean the output directory of irrelevant data. 66 67 self.check_output("debug=%r gc_sections=%r" % (debug, gc_sections)) 68 69 for module in self.importer.modules.values(): 70 output_filename = join(output, "%s.c" % module.name) 71 72 # Do not generate modules in the native package. They are provided 73 # by native functionality source files. 74 75 parts = module.name.split(".") 76 77 if parts[0] != "native" and \ 78 (reset or is_newer(module.filename, output_filename)): 79 80 tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser) 81 tm.translate(module.filename, output_filename) 82 83 84 85 def make_expression(expr): 86 87 "Make a new expression from the existing 'expr'." 88 89 if isinstance(expr, Result): 90 return expr 91 else: 92 return Expression(str(expr)) 93 94 95 96 # The actual translation process itself. 97 98 class TranslatedModule(CommonModule): 99 100 "A module translator." 101 102 def __init__(self, name, importer, deducer, optimiser): 103 CommonModule.__init__(self, name, importer) 104 self.deducer = deducer 105 self.optimiser = optimiser 106 107 # Output stream. 108 109 self.out_toplevel = self.out = None 110 self.indent = 0 111 self.tabstop = " " 112 113 # Recorded namespaces. 114 115 self.namespaces = [] 116 self.in_conditional = False 117 118 # Exception raising adjustments. 119 120 self.in_try_finally = False 121 self.in_try_except = False 122 123 # Invocation adjustments. 124 125 self.in_argument_list = False 126 127 # Attribute access and accessor counting. 128 129 self.attr_accesses = {} 130 self.attr_accessors = {} 131 132 # Special variable usage. 133 134 self.temp_usage = {} 135 136 # Initialise some data used for attribute access generation. 137 138 self.init_substitutions() 139 140 def __repr__(self): 141 return "TranslatedModule(%r, %r)" % (self.name, self.importer) 142 143 def translate(self, filename, output_filename): 144 145 """ 146 Parse the file having the given 'filename', writing the translation to 147 the given 'output_filename'. 148 """ 149 150 self.parse_file(filename) 151 152 # Collect function namespaces for separate processing. 153 154 self.record_namespaces(self.astnode) 155 156 # Reset the lambda naming (in order to obtain the same names again) and 157 # translate the program. 158 159 self.reset_lambdas() 160 161 self.out_toplevel = self.out = open(output_filename, "w") 162 try: 163 self.start_output() 164 165 # Process namespaces, writing the translation. 166 167 for path, node in self.namespaces: 168 self.process_namespace(path, node) 169 170 # Process the module namespace including class namespaces. 171 172 self.process_namespace([], self.astnode) 173 174 finally: 175 self.out.close() 176 177 def have_object(self): 178 179 "Return whether a namespace is a recorded object." 180 181 return self.importer.objects.get(self.get_namespace_path()) 182 183 def get_builtin_class(self, name): 184 185 "Return a reference to the actual object providing 'name'." 186 187 return self.importer.get_object(get_builtin_class(name)) 188 189 def is_method(self, path): 190 191 "Return whether 'path' is a method." 192 193 class_name, method_name = path.rsplit(".", 1) 194 return self.importer.classes.has_key(class_name) and class_name or None 195 196 def in_method(self): 197 198 "Return whether the current namespace provides a method." 199 200 return self.in_function and self.is_method(self.get_namespace_path()) 201 202 # Namespace recording. 203 204 def record_namespaces(self, node): 205 206 "Process the program structure 'node', recording namespaces." 207 208 for n in node.getChildNodes(): 209 self.record_namespaces_in_node(n) 210 211 def record_namespaces_in_node(self, node): 212 213 "Process the program structure 'node', recording namespaces." 214 215 # Function namespaces within modules, classes and other functions. 216 # Functions appearing within conditional statements are given arbitrary 217 # names. 218 219 if isinstance(node, compiler.ast.Function): 220 self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name) 221 222 elif isinstance(node, compiler.ast.Lambda): 223 self.record_function_node(node, self.get_lambda_name()) 224 225 # Classes are visited, but may be ignored if inside functions. 226 227 elif isinstance(node, compiler.ast.Class): 228 self.enter_namespace(node.name) 229 if self.have_object(): 230 self.record_namespaces(node) 231 self.exit_namespace() 232 233 # Conditional nodes are tracked so that function definitions may be 234 # handled. Since "for" loops are converted to "while" loops, they are 235 # included here. 236 237 elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)): 238 in_conditional = self.in_conditional 239 self.in_conditional = True 240 self.record_namespaces(node) 241 self.in_conditional = in_conditional 242 243 # All other nodes are processed depth-first. 244 245 else: 246 self.record_namespaces(node) 247 248 def record_function_node(self, n, name): 249 250 """ 251 Record the given function, lambda, if expression or list comprehension 252 node 'n' with the given 'name'. 253 """ 254 255 self.in_function = True 256 self.enter_namespace(name) 257 258 if self.have_object(): 259 260 # Record the namespace path and the node itself. 261 262 self.namespaces.append((self.namespace_path[:], n)) 263 self.record_namespaces_in_node(n.code) 264 265 self.exit_namespace() 266 self.in_function = False 267 268 # Constant referencing. 269 270 def get_literal_instance(self, n, name=None): 271 272 """ 273 For node 'n', return a reference for the type of the given 'name', or if 274 'name' is not specified, deduce the type from the value. 275 """ 276 277 # Handle stray None constants (Sliceobj seems to produce them). 278 279 if name is None and n.value is None: 280 return self.process_name_node(compiler.ast.Name("None")) 281 282 if name in ("dict", "list", "tuple"): 283 ref = self.get_builtin_class(name) 284 return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef) 285 else: 286 value, typename, encoding = self.get_constant_value(n.value, n.literals) 287 ref = self.get_builtin_class(typename) 288 value_type = ref.get_origin() 289 290 path = self.get_namespace_path() 291 292 # Obtain the local numbering of the constant and thus the 293 # locally-qualified name. 294 295 local_number = self.importer.all_constants[path][(value, value_type, encoding)] 296 constant_name = "$c%d" % local_number 297 objpath = self.get_object_path(constant_name) 298 299 # Obtain the unique identifier for the constant. 300 301 number = self.optimiser.constant_numbers[objpath] 302 return TrConstantValueRef(constant_name, ref.instance_of(), value, number) 303 304 # Namespace translation. 305 306 def process_namespace(self, path, node): 307 308 """ 309 Process the namespace for the given 'path' defined by the given 'node'. 310 """ 311 312 self.namespace_path = path 313 314 if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)): 315 self.in_function = True 316 self.process_function_body_node(node) 317 else: 318 self.in_function = False 319 self.function_target = 0 320 self.max_function_targets = 0 321 self.start_module() 322 self.process_structure(node) 323 self.end_module() 324 325 def process_structure(self, node): 326 327 "Process the given 'node' or result." 328 329 # Handle processing requests on results. 330 331 if isinstance(node, Result): 332 return node 333 334 # Handle processing requests on nodes. 335 336 else: 337 l = CommonModule.process_structure(self, node) 338 339 # Return indications of return statement usage. 340 341 if l and isinstance(l[-1], ReturnRef): 342 return l[-1] 343 else: 344 return None 345 346 def process_structure_node(self, n): 347 348 "Process the individual node 'n'." 349 350 # Plain statements emit their expressions. 351 352 if isinstance(n, compiler.ast.Discard): 353 expr = self.process_structure_node(n.expr) 354 self.statement(expr) 355 356 # Module import declarations. 357 358 elif isinstance(n, compiler.ast.From): 359 self.process_from_node(n) 360 361 # Nodes using operator module functions. 362 363 elif isinstance(n, compiler.ast.Operator): 364 return self.process_operator_node(n) 365 366 elif isinstance(n, compiler.ast.AugAssign): 367 self.process_augassign_node(n) 368 369 elif isinstance(n, compiler.ast.Compare): 370 return self.process_compare_node(n) 371 372 elif isinstance(n, compiler.ast.Slice): 373 return self.process_slice_node(n) 374 375 elif isinstance(n, compiler.ast.Sliceobj): 376 return self.process_sliceobj_node(n) 377 378 elif isinstance(n, compiler.ast.Subscript): 379 return self.process_subscript_node(n) 380 381 # Classes are visited, but may be ignored if inside functions. 382 383 elif isinstance(n, compiler.ast.Class): 384 self.process_class_node(n) 385 386 # Functions within namespaces have any dynamic defaults initialised. 387 388 elif isinstance(n, compiler.ast.Function): 389 self.process_function_node(n) 390 391 # Lambdas are replaced with references to separately-generated 392 # functions. 393 394 elif isinstance(n, compiler.ast.Lambda): 395 return self.process_lambda_node(n) 396 397 # Assignments. 398 399 elif isinstance(n, compiler.ast.Assign): 400 401 # Handle each assignment node. 402 403 for node in n.nodes: 404 self.process_assignment_node(node, n.expr) 405 406 # Accesses. 407 408 elif isinstance(n, compiler.ast.Getattr): 409 return self.process_attribute_access(n) 410 411 # Names. 412 413 elif isinstance(n, compiler.ast.Name): 414 return self.process_name_node(n) 415 416 # Loops and conditionals. 417 418 elif isinstance(n, compiler.ast.For): 419 self.process_for_node(n) 420 421 elif isinstance(n, compiler.ast.While): 422 self.process_while_node(n) 423 424 elif isinstance(n, compiler.ast.If): 425 self.process_if_node(n) 426 427 elif isinstance(n, (compiler.ast.And, compiler.ast.Or)): 428 return self.process_logical_node(n) 429 430 elif isinstance(n, compiler.ast.Not): 431 return self.process_not_node(n) 432 433 # Exception control-flow tracking. 434 435 elif isinstance(n, compiler.ast.TryExcept): 436 self.process_try_node(n) 437 438 elif isinstance(n, compiler.ast.TryFinally): 439 self.process_try_finally_node(n) 440 441 # Control-flow modification statements. 442 443 elif isinstance(n, compiler.ast.Break): 444 self.writestmt("break;") 445 446 elif isinstance(n, compiler.ast.Continue): 447 self.writestmt("continue;") 448 449 elif isinstance(n, compiler.ast.Raise): 450 self.process_raise_node(n) 451 452 elif isinstance(n, compiler.ast.Return): 453 return self.process_return_node(n) 454 455 # Print statements. 456 457 elif isinstance(n, (compiler.ast.Print, compiler.ast.Printnl)): 458 self.statement(self.process_print_node(n)) 459 460 # Invocations. 461 462 elif isinstance(n, compiler.ast.CallFunc): 463 return self.process_invocation_node(n) 464 465 elif isinstance(n, compiler.ast.Keyword): 466 return self.process_structure_node(n.expr) 467 468 # Constant usage. 469 470 elif isinstance(n, compiler.ast.Const): 471 return self.get_literal_instance(n) 472 473 elif isinstance(n, compiler.ast.Dict): 474 return self.get_literal_instance(n, "dict") 475 476 elif isinstance(n, compiler.ast.List): 477 return self.get_literal_instance(n, "list") 478 479 elif isinstance(n, compiler.ast.Tuple): 480 return self.get_literal_instance(n, "tuple") 481 482 # All other nodes are processed depth-first. 483 484 else: 485 return self.process_structure(n) 486 487 def process_assignment_node(self, n, expr): 488 489 "Process the individual node 'n' to be assigned the contents of 'expr'." 490 491 # Names and attributes are assigned the entire expression. 492 493 if isinstance(n, compiler.ast.AssName): 494 name_ref = self.process_name_node(n, self.process_structure_node(expr)) 495 self.statement(name_ref) 496 497 # Employ guards after assignments if required. 498 499 if expr and name_ref.is_name(): 500 self.generate_guard(name_ref.name) 501 502 elif isinstance(n, compiler.ast.AssAttr): 503 in_assignment = self.in_assignment 504 self.in_assignment = self.process_structure_node(expr) 505 self.statement(self.process_attribute_access(n)) 506 self.in_assignment = in_assignment 507 508 # Lists and tuples are matched against the expression and their 509 # items assigned to expression items. 510 511 elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)): 512 self.process_assignment_node_items(n, expr) 513 514 # Slices and subscripts are permitted within assignment nodes. 515 516 elif isinstance(n, compiler.ast.Slice): 517 self.statement(self.process_slice_node(n, expr)) 518 519 elif isinstance(n, compiler.ast.Subscript): 520 self.statement(self.process_subscript_node(n, expr)) 521 522 def process_attribute_access(self, n): 523 524 "Process the given attribute access node 'n'." 525 526 # Obtain any completed chain and return the reference to it. 527 528 attr_expr = self.process_attribute_chain(n) 529 if self.have_access_expression(n): 530 return attr_expr 531 532 # Where the start of the chain of attributes has been reached, process 533 # the complete access. 534 535 name_ref = attr_expr and attr_expr.is_name() and attr_expr 536 name = name_ref and self.get_name_for_tracking(name_ref.name, name_ref) or None 537 538 location = self.get_access_location(name, self.attrs) 539 refs = self.get_referenced_attributes(location) 540 541 # Generate access instructions. 542 543 subs = { 544 "<expr>" : attr_expr, 545 "<name>" : "%s.value" % attr_expr, 546 "<assexpr>" : self.in_assignment, 547 } 548 549 subs.update(self.temp_subs) 550 subs.update(self.op_subs) 551 552 output = [] 553 substituted = set() 554 555 # The context set or retrieved will be that used by any enclosing 556 # invocation. 557 558 context_index = self.function_target - 1 559 context_identity = None 560 561 # Obtain encoded versions of each instruction, accumulating temporary 562 # variables. 563 564 for instruction in self.deducer.access_instructions[location]: 565 566 # Intercept a special instruction identifying the context. 567 568 if instruction[0] == "<context_identity>": 569 context_identity, _substituted = encode_access_instruction_arg(instruction[1], subs, instruction[0], context_index) 570 continue 571 572 # Collect the encoded instruction, noting any temporary variables 573 # required by it. 574 575 encoded, _substituted = encode_access_instruction(instruction, subs, context_index) 576 output.append(encoded) 577 substituted.update(_substituted) 578 579 # Record temporary name usage. 580 581 for sub in substituted: 582 if self.temp_subs.has_key(sub): 583 self.record_temp(self.temp_subs[sub]) 584 585 del self.attrs[0] 586 return AttrResult(output, refs, location, context_identity) 587 588 def init_substitutions(self): 589 590 """ 591 Initialise substitutions, defining temporary variable mappings, some of 592 which are also used as substitutions, together with operation mappings 593 used as substitutions in instructions defined by the optimiser. 594 """ 595 596 self.temp_subs = { 597 598 # Substitutions used by instructions. 599 600 "<private_context>" : "__tmp_private_context", 601 "<accessor>" : "__tmp_value", 602 "<target_accessor>" : "__tmp_target_value", 603 604 # Mappings to be replaced by those given below. 605 606 "<context>" : "__tmp_contexts", 607 "<test_context_revert>" : "__tmp_contexts", 608 "<test_context_static>" : "__tmp_contexts", 609 "<set_context>" : "__tmp_contexts", 610 "<set_private_context>" : "__tmp_private_context", 611 "<set_accessor>" : "__tmp_value", 612 "<set_target_accessor>" : "__tmp_target_value", 613 } 614 615 self.op_subs = { 616 "<context>" : "__get_context", 617 "<test_context_revert>" : "__test_context_revert", 618 "<test_context_static>" : "__test_context_static", 619 "<set_context>" : "__set_context", 620 "<set_private_context>" : "__set_private_context", 621 "<set_accessor>" : "__set_accessor", 622 "<set_target_accessor>" : "__set_target_accessor", 623 } 624 625 def get_referenced_attributes(self, location): 626 627 """ 628 Convert 'location' to the form used by the deducer and retrieve any 629 identified attributes. 630 """ 631 632 access_location = self.deducer.const_accesses.get(location) 633 634 # Determine whether any deduced references refer to the accessed 635 # attribute. 636 637 path, accessor_name, attrnames, access_number = location 638 attrnames = attrnames and attrnames.split(".") 639 remaining = attrnames and len(attrnames) > 1 640 641 if remaining and not access_location: 642 return [] 643 644 refs = [] 645 l = self.deducer.referenced_attrs.get(access_location or location) 646 if l: 647 for attrtype, objpath, attr in l: 648 refs.append(attr) 649 return refs 650 651 def get_referenced_attribute_invocations(self, location): 652 653 """ 654 Convert 'location' to the form used by the deducer and retrieve any 655 identified attribute invocation details. 656 """ 657 658 access_location = self.deducer.const_accesses.get(location) 659 return self.deducer.reference_invocations_unsuitable.get(access_location or location) 660 661 def get_accessor_kinds(self, location): 662 663 "Return the accessor kinds for 'location'." 664 665 return self.deducer.accessor_kinds.get(location) 666 667 def get_access_location(self, name, attrnames=None): 668 669 """ 670 Using the current namespace, the given 'name', and the 'attrnames' 671 employed in an access, return the access location. 672 """ 673 674 path = self.get_path_for_access() 675 676 # Get the location used by the deducer and optimiser and find any 677 # recorded access. 678 679 attrnames = attrnames and ".".join(self.attrs) 680 access_number = self.get_access_number(path, name, attrnames) 681 self.update_access_number(path, name, attrnames) 682 return (path, name, attrnames, access_number) 683 684 def get_access_number(self, path, name, attrnames): 685 access = name, attrnames 686 if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access): 687 return self.attr_accesses[path][access] 688 else: 689 return 0 690 691 def update_access_number(self, path, name, attrnames): 692 access = name, attrnames 693 if name: 694 init_item(self.attr_accesses, path, dict) 695 init_item(self.attr_accesses[path], access, lambda: 0) 696 self.attr_accesses[path][access] += 1 697 698 def get_accessor_location(self, name): 699 700 """ 701 Using the current namespace and the given 'name', return the accessor 702 location. 703 """ 704 705 path = self.get_path_for_access() 706 707 # Get the location used by the deducer and optimiser and find any 708 # recorded accessor. 709 710 access_number = self.get_accessor_number(path, name) 711 self.update_accessor_number(path, name) 712 return (path, name, None, access_number) 713 714 def get_accessor_number(self, path, name): 715 if self.attr_accessors.has_key(path) and self.attr_accessors[path].has_key(name): 716 return self.attr_accessors[path][name] 717 else: 718 return 0 719 720 def update_accessor_number(self, path, name): 721 if name: 722 init_item(self.attr_accessors, path, dict) 723 init_item(self.attr_accessors[path], name, lambda: 0) 724 self.attr_accessors[path][name] += 1 725 726 def process_class_node(self, n): 727 728 "Process the given class node 'n'." 729 730 class_name = self.get_object_path(n.name) 731 732 # Where a class is set conditionally or where the name may refer to 733 # different values, assign the name. 734 735 ref = self.importer.identify(class_name) 736 737 if not ref.static(): 738 self.process_assignment_for_object(n.name, 739 make_expression("__ATTRVALUE(&%s)" % encode_path(class_name))) 740 741 self.enter_namespace(n.name) 742 743 if self.have_object(): 744 self.write_comment("Class: %s" % class_name) 745 746 self.initialise_inherited_members(class_name) 747 748 self.process_structure(n) 749 self.write_comment("End class: %s" % class_name) 750 751 self.exit_namespace() 752 753 def initialise_inherited_members(self, class_name): 754 755 "Initialise members of 'class_name' inherited from its ancestors." 756 757 for name, path in self.importer.all_class_attrs[class_name].items(): 758 target = "%s.%s" % (class_name, name) 759 760 # Ignore attributes with definitions. 761 762 ref = self.importer.identify(target) 763 if ref: 764 continue 765 766 # Ignore special type attributes. 767 768 if is_type_attribute(name): 769 continue 770 771 # Reference inherited attributes. 772 773 ref = self.importer.identify(path) 774 if ref and not ref.static(): 775 parent, attrname = path.rsplit(".", 1) 776 777 self.writestmt("__store_via_object(&%s, %s, __load_via_object(&%s, %s));" % ( 778 encode_path(class_name), name, 779 encode_path(parent), attrname 780 )) 781 782 def process_from_node(self, n): 783 784 "Process the given node 'n', importing from another module." 785 786 path = self.get_namespace_path() 787 788 # Attempt to obtain the referenced objects. 789 790 for name, alias in n.names: 791 if name == "*": 792 raise InspectError("Only explicitly specified names can be imported from modules.", path, n) 793 794 # Obtain the path of the assigned name. 795 796 objpath = self.get_object_path(alias or name) 797 798 # Obtain the identity of the name. 799 800 ref = self.importer.identify(objpath) 801 802 # Where the name is not static, assign the value. 803 804 if ref and not ref.static() and ref.get_name(): 805 self.writestmt("%s;" % 806 TrResolvedNameRef(alias or name, Reference("<var>", None, objpath), 807 expr=TrResolvedNameRef(name, ref))) 808 809 def process_function_body_node(self, n): 810 811 """ 812 Process the given function, lambda, if expression or list comprehension 813 node 'n', generating the body. 814 """ 815 816 function_name = self.get_namespace_path() 817 self.start_function(function_name) 818 819 # Process the function body. 820 821 in_conditional = self.in_conditional 822 self.in_conditional = False 823 self.function_target = 0 824 self.max_function_targets = 0 825 826 # Volatile locals for exception handling. 827 828 self.volatile_locals = set() 829 830 # Process any guards defined for the parameters. 831 832 for name in self.importer.function_parameters.get(function_name): 833 self.generate_guard(name) 834 835 # Produce the body and any additional return statement. 836 837 expr = self.process_structure_node(n.code) or PredefinedConstantRef("None") 838 if not isinstance(expr, ReturnRef): 839 self.writestmt("return %s;" % expr) 840 841 self.in_conditional = in_conditional 842 843 self.end_function(function_name) 844 845 def generate_guard(self, name): 846 847 """ 848 Get the accessor details for 'name', found in the current namespace, and 849 generate any guards defined for it. 850 """ 851 852 # Obtain the location, keeping track of assignment versions. 853 854 location = self.get_accessor_location(name) 855 test = self.deducer.accessor_guard_tests.get(location) 856 857 # Generate any guard from the deduced information. 858 859 if test: 860 guard, guard_type = test 861 862 if guard == "specific": 863 ref = first(self.deducer.accessor_all_types[location]) 864 argstr = "&%s" % encode_path(ref.get_origin()) 865 elif guard == "common": 866 ref = first(self.deducer.accessor_all_general_types[location]) 867 argstr = encode_path(encode_type_attribute(ref.get_origin())) 868 else: 869 return 870 871 # Produce an appropriate access to an attribute's value. 872 873 parameters = self.importer.function_parameters.get(self.get_namespace_path()) 874 if parameters and name in parameters: 875 name_to_value = "%s->value" % encode_path(name) 876 else: 877 name_to_value = "%s.value" % encode_path(name) 878 879 # Write a test that raises a TypeError upon failure. 880 881 self.writestmt("if (!__test_%s_%s(%s, %s)) __raise_type_error();" % ( 882 guard, guard_type, name_to_value, argstr)) 883 884 def process_function_node(self, n): 885 886 """ 887 Process the given function, lambda, if expression or list comprehension 888 node 'n', generating any initialisation statements. 889 """ 890 891 # Where a function is declared conditionally, use a separate name for 892 # the definition, and assign the definition to the stated name. 893 894 original_name = n.name 895 896 if self.in_conditional or self.in_function: 897 name = self.get_lambda_name() 898 else: 899 name = n.name 900 901 objpath = self.get_object_path(name) 902 903 # Obtain details of the defaults. 904 905 defaults = self.process_function_defaults(n, name, objpath) 906 if defaults: 907 for default in defaults: 908 self.writeline("%s;" % default) 909 910 # Where a function is set conditionally or where the name may refer to 911 # different values, assign the name. 912 913 ref = self.importer.identify(objpath) 914 915 if self.in_conditional or self.in_function: 916 self.process_assignment_for_object(original_name, compiler.ast.Name(name)) 917 elif not ref.static(): 918 context = self.is_method(objpath) 919 920 self.process_assignment_for_object(original_name, 921 make_expression("__ATTRVALUE(&%s)" % encode_path(objpath))) 922 923 def process_function_defaults(self, n, name, objpath, instance_name=None): 924 925 """ 926 Process the given function or lambda node 'n', initialising defaults 927 that are dynamically set. The given 'name' indicates the name of the 928 function. The given 'objpath' indicates the origin of the function. 929 The given 'instance_name' indicates the name of any separate instance 930 of the function created to hold the defaults. 931 932 Return a list of operations setting defaults on a function instance. 933 """ 934 935 function_name = self.get_object_path(name) 936 function_defaults = self.importer.function_defaults.get(function_name) 937 if not function_defaults: 938 return None 939 940 # Determine whether any unidentified defaults are involved. 941 942 for argname, default in function_defaults: 943 if not default.static(): 944 break 945 else: 946 return None 947 948 # Handle bound methods. 949 950 if not instance_name: 951 instance_name = "&%s" % encode_path(objpath) 952 953 # Where defaults are involved but cannot be identified, obtain a new 954 # instance of the lambda and populate the defaults. 955 956 defaults = [] 957 958 # Join the original defaults with the inspected defaults. 959 960 original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default] 961 962 for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)): 963 964 # Obtain any reference for the default. 965 966 if original: 967 argname, default = original 968 name_ref = self.process_structure_node(default) 969 elif inspected: 970 argname, default = inspected 971 name_ref = TrResolvedNameRef(argname, default) 972 else: 973 continue 974 975 # Generate default initialisers except when constants are employed. 976 # Constants should be used when populating the function structures. 977 978 if name_ref and not isinstance(name_ref, TrConstantValueRef): 979 defaults.append("__SETDEFAULT(%s, %s, %s)" % (instance_name, i, name_ref)) 980 981 return defaults 982 983 def process_if_node(self, n): 984 985 """ 986 Process the given "if" node 'n'. 987 """ 988 989 first = True 990 for test, body in n.tests: 991 test_ref = self.process_structure_node(test) 992 self.start_if(first, test_ref) 993 994 in_conditional = self.in_conditional 995 self.in_conditional = True 996 self.process_structure_node(body) 997 self.in_conditional = in_conditional 998 999 self.end_if() 1000 first = False 1001 1002 if n.else_: 1003 self.start_else() 1004 self.process_structure_node(n.else_) 1005 self.end_else() 1006 1007 print >>self.out 1008 1009 def process_invocation_node(self, n): 1010 1011 "Process the given invocation node 'n'." 1012 1013 # Any invocations in the expression will store target details in a 1014 # different location. 1015 1016 self.next_target() 1017 1018 in_argument_list = self.in_argument_list 1019 self.in_argument_list = False 1020 1021 # Process the expression. 1022 1023 expr = self.process_structure_node(n.node) 1024 1025 # Reference the current target again. 1026 1027 self.in_argument_list = in_argument_list 1028 self.function_target -= 1 1029 1030 # Obtain details of the invocation expression. 1031 1032 objpath = expr.get_origin() 1033 location = expr.access_location() 1034 refs = expr.references() 1035 1036 # Identified target details. 1037 1038 target = None 1039 target_structure = None 1040 1041 # Specific function target information. 1042 1043 function = None 1044 1045 # Instantiation involvement. 1046 1047 instantiation = False 1048 literal_instantiation = False 1049 1050 # Invocation requirements. 1051 1052 context_required = True 1053 have_access_context = isinstance(expr, AttrResult) 1054 context_identity = have_access_context and expr.context() 1055 parameters = None 1056 1057 # Obtain details of the callable and of its parameters. 1058 1059 # Literals may be instantiated specially. 1060 1061 if expr.is_name() and expr.name.startswith("$L") and objpath: 1062 instantiation = literal_instantiation = objpath 1063 target = encode_literal_instantiator(objpath) 1064 context_required = False 1065 1066 # Identified targets employ function pointers directly. 1067 1068 elif objpath: 1069 parameters = self.importer.function_parameters.get(objpath) 1070 function_defaults = self.importer.function_defaults.get(objpath) 1071 1072 # Class invocation involves instantiators. 1073 1074 if expr.has_kind("<class>"): 1075 instantiation = objpath 1076 target = encode_instantiator_pointer(objpath) 1077 init_ref = self.importer.all_class_attrs[objpath]["__init__"] 1078 target_structure = "&%s" % encode_path(init_ref) 1079 context_required = False 1080 1081 # Only plain functions and bound methods employ function pointers. 1082 1083 elif expr.has_kind("<function>"): 1084 function = objpath 1085 1086 # Test for functions and methods. 1087 1088 context_required = self.is_method(objpath) 1089 1090 accessor_kinds = location and self.get_accessor_kinds(location) 1091 1092 instance_accessor = accessor_kinds and \ 1093 len(accessor_kinds) == 1 and \ 1094 first(accessor_kinds) == "<instance>" 1095 1096 # Only identify certain bound methods or functions. 1097 1098 if not context_required or instance_accessor: 1099 target = encode_function_pointer(objpath) 1100 1101 # Access bound method defaults even if it is not clear whether 1102 # the accessor is appropriate. 1103 1104 target_structure = "&%s" % encode_path(objpath) 1105 1106 # Other targets are retrieved at run-time. 1107 1108 else: 1109 if location: 1110 path, name, attrnames, access_number = location 1111 attrname = attrnames and attrnames.rsplit(".", 1)[-1] 1112 1113 # Determine any common aspects of any attribute. 1114 1115 if attrname: 1116 all_params = set() 1117 all_defaults = set() 1118 refs = set() 1119 1120 # Obtain parameters and defaults for each possible target. 1121 1122 for ref in self.get_attributes_for_attrname(attrname): 1123 refs.add(ref) 1124 origin = ref.get_origin() 1125 params = self.importer.function_parameters.get(origin) 1126 if params: 1127 all_params.add(tuple(params)) 1128 defaults = self.importer.function_defaults.get(origin) 1129 if defaults: 1130 all_defaults.add(tuple(defaults)) 1131 1132 # Where the parameters and defaults are always the same, 1133 # permit populating them in advance. 1134 1135 if len(all_params) == 1 and (not all_defaults or len(all_defaults) == 1): 1136 parameters = first(all_params) 1137 function_defaults = all_defaults and first(all_defaults) or [] 1138 1139 # Some information about the target may be available and be used to 1140 # provide warnings about argument compatibility. 1141 1142 if self.importer.give_warning("args"): 1143 unsuitable = self.get_referenced_attribute_invocations(location) 1144 1145 if unsuitable: 1146 for ref in unsuitable: 1147 _objpath = ref.get_origin() 1148 num_parameters = len(self.importer.function_parameters[_objpath]) 1149 print >>sys.stderr, \ 1150 "In %s, at line %d, inappropriate number of " \ 1151 "arguments given. Need %d arguments to call %s." % ( 1152 self.get_namespace_path(), n.lineno, num_parameters, 1153 _objpath) 1154 1155 # Determine any readily-accessible target identity. 1156 1157 target_named = expr.is_name() and str(expr) or None 1158 target_stored = "__tmp_targets[%d]" % self.function_target 1159 1160 target_identity = target or target_named 1161 target_var = target_identity or target_stored 1162 context_var = target_named or target_stored 1163 1164 if not target_identity: 1165 self.record_temp("__tmp_targets") 1166 1167 if context_identity and context_identity.startswith("__tmp_contexts"): 1168 self.record_temp("__tmp_contexts") 1169 1170 # Arguments are presented in a temporary frame array with any context 1171 # always being the first argument. Where it would be unused, it may be 1172 # set to null. 1173 1174 if context_required: 1175 if have_access_context: 1176 args = ["__ATTRVALUE(%s)" % context_identity] 1177 else: 1178 args = ["__CONTEXT_AS_VALUE(%s)" % context_var] 1179 else: 1180 args = ["__NULL"] 1181 1182 # Complete the array with null values, permitting tests for a complete 1183 # set of arguments. 1184 1185 args += [None] * (parameters is None and len(n.args) or parameters is not None and len(parameters) or 0) 1186 kwcodes = [] 1187 kwargs = [] 1188 1189 # Any invocations in the arguments will store target details in a 1190 # different location. 1191 1192 function_target = self.function_target 1193 1194 if not target_identity: 1195 self.next_target() 1196 1197 in_argument_list = self.in_argument_list 1198 self.in_argument_list = True 1199 1200 for i, arg in enumerate(n.args): 1201 argexpr = self.process_structure_node(arg) 1202 1203 # Store a keyword argument, either in the argument list or 1204 # in a separate keyword argument list for subsequent lookup. 1205 1206 if isinstance(arg, compiler.ast.Keyword): 1207 1208 # With knowledge of the target, store the keyword 1209 # argument directly. 1210 1211 if parameters: 1212 try: 1213 argnum = parameters.index(arg.name) 1214 except ValueError: 1215 raise TranslateError("Argument %s is not recognised." % arg.name, 1216 self.get_namespace_path(), n) 1217 args[argnum+1] = str(argexpr) 1218 1219 # Otherwise, store the details in a separate collection. 1220 1221 else: 1222 kwargs.append(str(argexpr)) 1223 kwcodes.append("{%s, %s}" % ( 1224 encode_ppos(arg.name), encode_pcode(arg.name))) 1225 1226 # Store non-keyword arguments in the argument list, rejecting 1227 # superfluous arguments. 1228 1229 else: 1230 try: 1231 args[i+1] = str(argexpr) 1232 except IndexError: 1233 raise TranslateError("Too many arguments specified.", 1234 self.get_namespace_path(), n) 1235 1236 # Reference the current target again. 1237 1238 self.in_argument_list = in_argument_list 1239 1240 if not self.in_argument_list: 1241 self.function_target = function_target 1242 1243 # Defaults are added to the frame where arguments are missing. 1244 1245 if parameters and function_defaults: 1246 target_structure = target_structure or "%s.value" % target_var 1247 1248 # Visit each default and set any missing arguments. 1249 # Use the target structure to obtain defaults, as opposed to the 1250 # actual function involved. 1251 1252 for i, (argname, default) in enumerate(function_defaults): 1253 argnum = parameters.index(argname) 1254 if not args[argnum+1]: 1255 args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target_structure, i) 1256 1257 # Test for missing arguments. 1258 1259 if None in args: 1260 raise TranslateError("Not all arguments supplied.", 1261 self.get_namespace_path(), n) 1262 1263 # Encode the arguments. 1264 1265 argstr = "__ARGS(%s)" % ", ".join(args) 1266 kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0" 1267 kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0" 1268 1269 # Where literal instantiation is occurring, add an argument indicating 1270 # the number of values. 1271 1272 if literal_instantiation: 1273 argstr += ", %d" % (len(args) - 1) 1274 1275 # First, the invocation expression is presented. 1276 1277 stages = [] 1278 1279 # Without a known specific callable, the expression provides the target. 1280 1281 if not target or context_required: 1282 1283 # The context is set in the expression. 1284 1285 if target and not target_named: 1286 1287 # Test whether the expression provides anything. 1288 1289 if expr: 1290 stages.append(str(expr)) 1291 1292 elif not target_identity: 1293 stages.append("%s = %s" % (target_var, expr)) 1294 1295 # Any specific callable is then obtained for invocation. 1296 1297 if target: 1298 stages.append(target) 1299 1300 # Methods accessed via unidentified accessors are obtained for 1301 # invocation. 1302 1303 elif function: 1304 if context_required: 1305 if have_access_context: 1306 stages.append("__get_function(%s, %s)" % ( 1307 context_identity, target_var)) 1308 elif context_var == target_var: 1309 stages.append("__get_function_unchecked(%s)" % target_var) 1310 else: 1311 stages.append("__get_function(__CONTEXT_AS_VALUE(%s).value, %s)" % ( 1312 context_var, target_var)) 1313 else: 1314 stages.append("__load_via_object(%s.value, __fn__).fn" % target_var) 1315 1316 # With known parameters, the target can be tested. 1317 1318 elif parameters: 1319 context_arg = context_required and args[0] or "__NULL" 1320 if self.always_callable(refs): 1321 if context_var == target_var: 1322 stages.append("__get_function_unchecked(%s)" % target_var) 1323 else: 1324 stages.append("__get_function(%s.value, %s)" % (context_arg, target_var)) 1325 else: 1326 stages.append("__check_and_get_function(%s.value, %s)" % (context_arg, target_var)) 1327 1328 # With a known target, the function is obtained directly and called. 1329 # By putting the invocation at the end of the final element in the 1330 # instruction sequence (the stages), the result becomes the result of 1331 # the sequence. Moreover, the parameters become part of the sequence 1332 # and thereby participate in a guaranteed evaluation order. 1333 1334 if target or function or parameters: 1335 stages[-1] += "(%s)" % argstr 1336 if instantiation: 1337 return InstantiationResult(instantiation, stages) 1338 else: 1339 return InvocationResult(stages) 1340 1341 # With unknown targets, the generic invocation function is applied to 1342 # the callable and argument collections. 1343 1344 else: 1345 stages.append("__invoke(\n%s,\n%d, %d, %s, %s,\n%d, %s\n)" % ( 1346 target_var, 1347 self.always_callable(refs) and 1 or 0, 1348 len(kwargs), kwcodestr, kwargstr, 1349 len(args), argstr)) 1350 return InvocationResult(stages) 1351 1352 def next_target(self): 1353 1354 "Allocate the next function target storage." 1355 1356 self.function_target += 1 1357 self.max_function_targets = max(self.function_target, self.max_function_targets) 1358 1359 def always_callable(self, refs): 1360 1361 "Determine whether all 'refs' are callable." 1362 1363 if not refs: 1364 return False 1365 1366 for ref in refs: 1367 if not ref.has_kind("<function>") and not self.importer.get_attributes(ref, "__fn__"): 1368 return False 1369 1370 return True 1371 1372 def need_default_arguments(self, objpath, nargs): 1373 1374 """ 1375 Return whether any default arguments are needed when invoking the object 1376 given by 'objpath'. 1377 """ 1378 1379 parameters = self.importer.function_parameters.get(objpath) 1380 return nargs < len(parameters) 1381 1382 def get_attributes_for_attrname(self, attrname): 1383 1384 "Return a set of all attributes exposed by 'attrname'." 1385 1386 usage = [(attrname, True, False)] 1387 class_types = self.deducer.get_class_types_for_usage(usage) 1388 instance_types = self.deducer.get_instance_types_for_usage(usage) 1389 module_types = self.deducer.get_module_types_for_usage(usage) 1390 attrs = set() 1391 1392 for ref in combine_types(class_types, instance_types, module_types): 1393 attrs.update(self.importer.get_attributes(ref, attrname)) 1394 1395 return attrs 1396 1397 def process_lambda_node(self, n): 1398 1399 "Process the given lambda node 'n'." 1400 1401 name = self.get_lambda_name() 1402 function_name = self.get_object_path(name) 1403 1404 defaults = self.process_function_defaults(n, name, function_name, "__tmp_value") 1405 1406 # Without defaults, produce an attribute referring to the function. 1407 1408 if not defaults: 1409 return make_expression("__ATTRVALUE(&%s)" % encode_path(function_name)) 1410 1411 # With defaults, copy the function structure and set the defaults on the 1412 # copy. 1413 1414 else: 1415 self.record_temp("__tmp_value") 1416 return make_expression("(__tmp_value = __COPY(&%s, sizeof(%s)), %s, __ATTRVALUE(__tmp_value))" % ( 1417 encode_path(function_name), 1418 encode_symbol("obj", function_name), 1419 ", ".join(defaults))) 1420 1421 def process_logical_node(self, n): 1422 1423 "Process the given operator node 'n'." 1424 1425 self.record_temp("__tmp_result") 1426 1427 conjunction = isinstance(n, compiler.ast.And) 1428 results = [] 1429 1430 for node in n.nodes: 1431 results.append(self.process_structure_node(node)) 1432 1433 return LogicalOperationResult(results, conjunction) 1434 1435 def process_name_node(self, n, expr=None): 1436 1437 "Process the given name node 'n' with the optional assignment 'expr'." 1438 1439 # Determine whether the name refers to a static external entity. 1440 1441 if n.name in predefined_constants: 1442 return PredefinedConstantRef(n.name, expr) 1443 1444 # Convert literal references, operator function names, and print 1445 # function names to references. 1446 1447 elif n.name.startswith("$L") or n.name.startswith("$op") or \ 1448 n.name.startswith("$print"): 1449 1450 ref, paths = self.importer.get_module(self.name).special[n.name] 1451 return TrResolvedNameRef(n.name, ref) 1452 1453 # Get the appropriate name for the name reference, using the same method 1454 # as in the inspector. 1455 1456 path = self.get_namespace_path() 1457 objpath = self.get_object_path(n.name) 1458 1459 # Determine any assigned globals. 1460 1461 globals = self.importer.get_module(self.name).scope_globals.get(path) 1462 1463 # Explicitly declared globals. 1464 1465 if globals and n.name in globals: 1466 objpath = self.get_global_path(n.name) 1467 is_global = True 1468 1469 # Implicitly referenced globals in functions. 1470 1471 elif self.in_function: 1472 is_global = n.name not in self.importer.function_locals[path] 1473 1474 # Implicitly referenced globals elsewhere. 1475 1476 else: 1477 namespace = self.importer.identify(path) 1478 is_global = not self.importer.get_attributes(namespace, n.name) 1479 1480 # Get the static identity of the name. 1481 1482 ref = self.importer.identify(objpath) 1483 if ref and not ref.get_name(): 1484 ref = ref.alias(objpath) 1485 1486 # Obtain any resolved names for non-assignment names. 1487 1488 if not expr and not ref and self.in_function: 1489 locals = self.importer.function_locals.get(path) 1490 ref = locals and locals.get(n.name) 1491 1492 # Determine whether the name refers to a parameter. The generation of 1493 # parameter references is different from other names. 1494 1495 parameters = self.importer.function_parameters.get(path) 1496 parameter = n.name == "self" and self.in_method() or \ 1497 parameters and n.name in parameters 1498 1499 # Find any invocation or alias details. 1500 1501 name = self.get_name_for_tracking(n.name, is_global=is_global) 1502 location = not expr and self.get_access_location(name) or None 1503 1504 # Mark any local assignments as volatile in exception blocks. 1505 1506 if expr and self.in_function and not is_global and self.in_try_except: 1507 self.make_volatile(n.name) 1508 1509 # Qualified names are used for resolved static references or for 1510 # static namespace members. The reference should be configured to return 1511 # such names. 1512 1513 name_ref = TrResolvedNameRef(n.name, ref, expr=expr, is_global=is_global, 1514 parameter=parameter, location=location) 1515 return not expr and self.get_aliases(name_ref) or name_ref 1516 1517 def get_aliases(self, name_ref): 1518 1519 "Return alias references for the given 'name_ref'." 1520 1521 location = name_ref.access_location() 1522 1523 refs = self.deducer.referenced_objects.get(location) 1524 refs = refs or self.deducer.accessor_all_types.get(location) 1525 return AliasResult(name_ref, refs or set(), location) 1526 1527 def make_volatile(self, name): 1528 1529 "Record 'name' as volatile in the current namespace." 1530 1531 self.volatile_locals.add(name) 1532 1533 def process_not_node(self, n): 1534 1535 "Process the given operator node 'n'." 1536 1537 return self.make_negation(self.process_structure_node(n.expr)) 1538 1539 def process_raise_node(self, n): 1540 1541 "Process the given raise node 'n'." 1542 1543 # NOTE: Determine which raise statement variants should be permitted. 1544 1545 if n.expr1: 1546 1547 # Names with accompanying arguments are treated like invocations. 1548 1549 if n.expr2: 1550 call = compiler.ast.CallFunc(n.expr1, [n.expr2]) 1551 exc = self.process_structure_node(call) 1552 self.writestmt("__Raise(%s);" % exc) 1553 1554 # Raise instances, testing the kind at run-time if necessary and 1555 # instantiating any non-instance. 1556 1557 else: 1558 exc = self.process_structure_node(n.expr1) 1559 1560 if isinstance(exc, TrInstanceRef): 1561 self.writestmt("__Raise(%s);" % exc) 1562 else: 1563 self.writestmt("__Raise(__ensure_instance(%s));" % exc) 1564 else: 1565 self.writestmt("__Throw(__tmp_exc);") 1566 1567 def process_return_node(self, n): 1568 1569 "Process the given return node 'n'." 1570 1571 expr = self.process_structure_node(n.value) or PredefinedConstantRef("None") 1572 if self.in_try_finally or self.in_try_except: 1573 self.writestmt("__Return(%s);" % expr) 1574 else: 1575 self.writestmt("return %s;" % expr) 1576 1577 return ReturnRef() 1578 1579 def process_try_node(self, n): 1580 1581 """ 1582 Process the given "try...except" node 'n'. 1583 """ 1584 1585 in_try_except = self.in_try_except 1586 self.in_try_except = True 1587 1588 # Use macros to implement exception handling. 1589 1590 self.writestmt("__Try") 1591 self.writeline("{") 1592 self.indent += 1 1593 self.process_structure_node(n.body) 1594 1595 # Put the else statement in another try block that handles any raised 1596 # exceptions and converts them to exceptions that will not be handled by 1597 # the main handling block. 1598 1599 if n.else_: 1600 self.writestmt("__Try") 1601 self.writeline("{") 1602 self.indent += 1 1603 self.process_structure_node(n.else_) 1604 self.indent -= 1 1605 self.writeline("}") 1606 self.writeline("__Catch (__tmp_exc)") 1607 self.writeline("{") 1608 self.indent += 1 1609 self.writeline("if (__tmp_exc.raising) __RaiseElse(__tmp_exc.arg);") 1610 self.writeline("else if (__tmp_exc.completing) __Throw(__tmp_exc);") 1611 self.indent -= 1 1612 self.writeline("}") 1613 1614 # Complete the try block and enter the finally block, if appropriate. 1615 1616 if self.in_try_finally: 1617 self.writestmt("__Complete;") 1618 1619 self.indent -= 1 1620 self.writeline("}") 1621 1622 self.in_try_except = in_try_except 1623 1624 # Handlers are tests within a common handler block. 1625 1626 self.writeline("__Catch (__tmp_exc)") 1627 self.writeline("{") 1628 self.indent += 1 1629 1630 # Introduce an if statement to handle the completion of a try block. 1631 1632 self.process_try_completion() 1633 1634 # Handle exceptions in else blocks converted to __RaiseElse, converting 1635 # them back to normal exceptions. 1636 1637 if n.else_: 1638 self.writeline("else if (__tmp_exc.raising_else) __Raise(__tmp_exc.arg);") 1639 1640 # Exception handling. 1641 1642 for name, var, handler in n.handlers: 1643 1644 # Test for specific exceptions. 1645 1646 if name is not None: 1647 name_ref = self.process_structure_node(name) 1648 self.writeline("else if (__ISINSTANCE(__tmp_exc.arg, %s))" % name_ref) 1649 else: 1650 self.writeline("else if (1)") 1651 1652 self.writeline("{") 1653 self.indent += 1 1654 1655 # Establish the local for the handler. 1656 1657 if var is not None: 1658 self.writestmt("%s;" % self.process_name_node(var, make_expression("__tmp_exc.arg"))) 1659 1660 if handler is not None: 1661 self.process_structure_node(handler) 1662 1663 self.indent -= 1 1664 self.writeline("}") 1665 1666 # Re-raise unhandled exceptions. 1667 1668 self.writeline("else __Throw(__tmp_exc);") 1669 1670 # End the handler block. 1671 1672 self.indent -= 1 1673 self.writeline("}") 1674 print >>self.out 1675 1676 def process_try_finally_node(self, n): 1677 1678 """ 1679 Process the given "try...finally" node 'n'. 1680 """ 1681 1682 in_try_finally = self.in_try_finally 1683 self.in_try_finally = True 1684 1685 # Use macros to implement exception handling. 1686 1687 self.writestmt("__Try") 1688 self.writeline("{") 1689 self.indent += 1 1690 self.process_structure_node(n.body) 1691 self.indent -= 1 1692 self.writeline("}") 1693 1694 self.in_try_finally = in_try_finally 1695 1696 # Finally clauses handle special exceptions. 1697 1698 self.writeline("__Catch (__tmp_exc)") 1699 self.writeline("{") 1700 self.indent += 1 1701 self.process_structure_node(n.final) 1702 1703 # Introduce an if statement to handle the completion of a try block. 1704 1705 self.process_try_completion() 1706 self.writeline("else __Throw(__tmp_exc);") 1707 1708 self.indent -= 1 1709 self.writeline("}") 1710 print >>self.out 1711 1712 def process_try_completion(self): 1713 1714 "Generate a test for the completion of a try block." 1715 1716 self.writestmt("if (__tmp_exc.completing)") 1717 self.writeline("{") 1718 self.indent += 1 1719 1720 # Do not return anything at the module level. 1721 1722 if self.get_namespace_path() != self.name: 1723 1724 # Only use the normal return statement if no surrounding try blocks 1725 # apply. 1726 1727 if not self.in_try_finally and not self.in_try_except: 1728 self.writeline("if (!__ISNULL(__tmp_exc.arg)) return __tmp_exc.arg;") 1729 else: 1730 self.writeline("if (!__ISNULL(__tmp_exc.arg)) __Throw(__tmp_exc);") 1731 1732 self.indent -= 1 1733 self.writeline("}") 1734 1735 def process_while_node(self, n): 1736 1737 "Process the given while node 'n'." 1738 1739 self.writeline("while (1)") 1740 self.writeline("{") 1741 self.indent += 1 1742 test = self.process_structure_node(n.test) 1743 1744 # Emit the loop termination condition unless "while <true value>" is 1745 # indicated. 1746 1747 if not (isinstance(test, PredefinedConstantRef) and test.value): 1748 1749 # Emit a negated test of the continuation condition. 1750 1751 self.start_if(True, self.make_negation(test)) 1752 if n.else_: 1753 self.process_structure_node(n.else_) 1754 self.writestmt("break;") 1755 self.end_if() 1756 1757 in_conditional = self.in_conditional 1758 self.in_conditional = True 1759 self.process_structure_node(n.body) 1760 self.in_conditional = in_conditional 1761 1762 self.indent -= 1 1763 self.writeline("}") 1764 print >>self.out 1765 1766 # Special variable usage. 1767 1768 def get_temp_path(self): 1769 1770 """ 1771 Return the appropriate namespace path for temporary names in the current 1772 namespace. 1773 """ 1774 1775 if self.in_function: 1776 return self.get_namespace_path() 1777 else: 1778 return self.name 1779 1780 def record_temp(self, name): 1781 1782 """ 1783 Record the use of the temporary 'name' in the current namespace. At the 1784 class or module level, the temporary name is associated with the module, 1785 since the variable will then be allocated in the module's own main 1786 program. 1787 """ 1788 1789 path = self.get_temp_path() 1790 1791 init_item(self.temp_usage, path, list) 1792 self.temp_usage[path].append(name) 1793 1794 def remove_temps(self, names): 1795 1796 """ 1797 Remove 'names' from temporary storage allocations, each instance 1798 removing each request for storage. 1799 """ 1800 1801 path = self.get_temp_path() 1802 1803 for name in names: 1804 if self.uses_temp(path, name): 1805 self.temp_usage[path].remove(name) 1806 1807 def uses_temp(self, path, name): 1808 1809 """ 1810 Return whether the given namespace 'path' employs a temporary variable 1811 with the given 'name'. Note that 'path' should only be a module or a 1812 function or method, not a class. 1813 """ 1814 1815 return self.temp_usage.has_key(path) and name in self.temp_usage[path] 1816 1817 def make_negation(self, expr): 1818 1819 "Return a negated form of 'expr'." 1820 1821 result = NegationResult(expr) 1822 1823 # Negation discards the temporary results of its operand. 1824 1825 temps = expr.discards_temporary() 1826 if temps: 1827 self.remove_temps(temps) 1828 1829 return result 1830 1831 # Output generation. 1832 1833 def start_output(self): 1834 1835 "Write the declarations at the top of each source file." 1836 1837 print >>self.out, """\ 1838 #include "types.h" 1839 #include "exceptions.h" 1840 #include "ops.h" 1841 #include "progconsts.h" 1842 #include "progops.h" 1843 #include "progtypes.h" 1844 #include "main.h" 1845 """ 1846 1847 def start_unit(self): 1848 1849 "Record output within a generated function for later use." 1850 1851 self.out = StringIO() 1852 1853 def end_unit(self): 1854 1855 "Restore the output stream." 1856 1857 out = self.out 1858 self.out = self.out_toplevel 1859 return out 1860 1861 def flush_unit(self, name, out): 1862 1863 "Add declarations and generated code." 1864 1865 self.write_temporaries(name) 1866 print >>self.out 1867 out.seek(0) 1868 self.out.write(out.read()) 1869 1870 def start_module(self): 1871 1872 "Write the start of each module's main function." 1873 1874 print >>self.out, "void __main_%s()" % encode_path(self.name) 1875 print >>self.out, "{" 1876 self.indent += 1 1877 1878 # Define temporary variables, excluded from the module structure itself. 1879 1880 tempnames = [] 1881 1882 for n in self.importer.all_module_attrs[self.name]: 1883 if n.startswith("$t"): 1884 tempnames.append(encode_path(n)) 1885 1886 if tempnames: 1887 tempnames.sort() 1888 self.writeline("__attr %s;" % ", ".join(tempnames)) 1889 1890 self.start_unit() 1891 1892 def end_module(self): 1893 1894 "End each module by closing its main function." 1895 1896 out = self.end_unit() 1897 self.flush_unit(self.name, out) 1898 1899 self.indent -= 1 1900 print >>self.out, "}" 1901 1902 def start_function(self, name): 1903 1904 "Start the function having the given 'name'." 1905 1906 print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name) 1907 print >>self.out, "{" 1908 self.indent += 1 1909 1910 self.start_unit() 1911 1912 def end_function(self, name): 1913 1914 "End the function having the given 'name'." 1915 1916 out = self.end_unit() 1917 1918 # Obtain local names from parameters. 1919 1920 parameters = self.importer.function_parameters[name] 1921 locals = self.importer.function_locals[name].keys() 1922 names = [] 1923 volatile_names = [] 1924 1925 for n in locals: 1926 1927 # Filter out special names and parameters. Note that self is a local 1928 # regardless of whether it originally appeared in the parameters or 1929 # not. 1930 1931 if n.startswith("$l") or n in parameters or n == "self": 1932 continue 1933 if n in self.volatile_locals: 1934 volatile_names.append(encode_path(n)) 1935 else: 1936 names.append(encode_path(n)) 1937 1938 # Emit required local names. 1939 1940 if names: 1941 names.sort() 1942 self.writeline("__attr %s;" % ", ".join(names)) 1943 1944 if volatile_names: 1945 volatile_names.sort() 1946 self.writeline("volatile __attr %s;" % ", ".join(volatile_names)) 1947 1948 self.write_parameters(name) 1949 1950 self.flush_unit(name, out) 1951 1952 self.indent -= 1 1953 print >>self.out, "}" 1954 print >>self.out 1955 1956 def write_temporaries(self, name): 1957 1958 "Write temporary storage employed by 'name'." 1959 1960 # Provide space for the given number of targets. 1961 1962 targets = self.max_function_targets 1963 1964 if self.uses_temp(name, "__tmp_targets"): 1965 self.writeline("__attr __tmp_targets[%d];" % targets) 1966 if self.uses_temp(name, "__tmp_contexts"): 1967 self.writeline("__ref __tmp_contexts[%d];" % targets) 1968 1969 # Add temporary variable usage details. 1970 1971 if self.uses_temp(name, "__tmp_private_context"): 1972 self.writeline("__ref __tmp_private_context;") 1973 if self.uses_temp(name, "__tmp_value"): 1974 self.writeline("__ref __tmp_value;") 1975 if self.uses_temp(name, "__tmp_target_value"): 1976 self.writeline("__ref __tmp_target_value;") 1977 if self.uses_temp(name, "__tmp_result"): 1978 self.writeline("__attr __tmp_result;") 1979 1980 module = self.importer.get_module(self.name) 1981 1982 if name in module.exception_namespaces: 1983 self.writeline("__exc __tmp_exc;") 1984 1985 def write_parameters(self, name): 1986 1987 """ 1988 For the function having the given 'name', write definitions of 1989 parameters found in the arguments array. 1990 """ 1991 1992 parameters = self.importer.function_parameters[name] 1993 1994 # Generate any self reference. 1995 1996 if self.is_method(name): 1997 self.writeline("__attr * const self = &__args[0];") 1998 1999 # Generate aliases for the parameters. 2000 2001 for i, parameter in enumerate(parameters): 2002 self.writeline("%s__attr * const %s = &__args[%d];" % ( 2003 parameter in self.volatile_locals and "volatile " or "", 2004 encode_path(parameter), i+1)) 2005 2006 def start_if(self, first, test_ref): 2007 statement = "%sif" % (not first and "else " or "") 2008 2009 # Consume logical results directly. 2010 2011 if isinstance(test_ref, LogicalResult): 2012 self.writeline("%s %s" % (statement, test_ref.apply_test())) 2013 temps = test_ref.discards_temporary() 2014 if temps: 2015 self.remove_temps(temps) 2016 else: 2017 self.writeline("%s (__BOOL(%s))" % (statement, test_ref)) 2018 2019 self.writeline("{") 2020 self.indent += 1 2021 2022 def end_if(self): 2023 self.indent -= 1 2024 self.writeline("}") 2025 2026 def start_else(self): 2027 self.writeline("else") 2028 self.writeline("{") 2029 self.indent += 1 2030 2031 def end_else(self): 2032 self.indent -= 1 2033 self.writeline("}") 2034 2035 def statement(self, expr): 2036 s = str(expr) 2037 if s: 2038 self.writestmt("%s;" % s) 2039 2040 def statements(self, results): 2041 for result in results: 2042 self.statement(result) 2043 2044 def writeline(self, s): 2045 print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1)) 2046 2047 def writestmt(self, s): 2048 self.writeline(s) 2049 2050 def write_comment(self, s): 2051 self.writestmt("/* %s */" % s) 2052 2053 def pad(self, extra=0): 2054 return (self.indent + extra) * self.tabstop 2055 2056 def indenttext(self, s, levels): 2057 lines = s.split("\n") 2058 out = [lines[0]] 2059 for line in lines[1:]: 2060 out.append(levels * self.tabstop + line) 2061 if line.endswith("("): 2062 levels += 1 2063 elif line.startswith(")"): 2064 levels -= 1 2065 return "\n".join(out) 2066 2067 # vim: tabstop=4 expandtab shiftwidth=4